Let Amplifier Installation Kit be an open subset of with finite Lebesgue -measure, let be the distance from to the boundary of , and let.We give a simple direct proof that if satisfies the plumpness condition of Martio and Väisälä [10], then Fireguard the inequality of Hardy type, holds whenever.We also show that the plumpness condition may be replaced by ones.which enable domains with lower-dimensional portions of their boundaries to be handled.